Amazon.com: HP EliteBook 840 G1 14in HD Business Laptop Computer Ultrabook, Intel Core i5-4300U 1.9 GHz Processor, 8GB RAM, 128GB SSD, USB 3.0, VGA, Wifi, RJ45, Windows 10 Professional (Renewed) : Electronics
OSCOO 256GB m.2 2242 Solid State Drive Disk High Speed SATA3 6GB/s ON800 SSD mSATA Double Cut Small Internal SSD with 3 Year Warranty Compatible for for Hp 840 G1 G2, 9480M,
HP EliteBook 840 G4 14" Touch Screen Laptop Core i5
How to install SSD in HP Elitebook 840 G1 Hard Drive replacement - YouTube